Chitosan-based edible film incorporated with wampee (Clausena lansium) seed essential oil: Preparation, characterization and biological activities

Chitosan (Ch)-based edible composite films were prepared by incorporating blending wampee seed essential oil (WSEO) into a Ch matrix, using the incorporation ratio as a variable. The physical, mechanical properties, structure morphology and rheological properties were determined using tensile strength (TS), elongation at break (EB), water vapor permeability (WVP) tests together with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) observations and apparent viscosity and shear rate. In addition, the antimicrobial, antioxidant activities were investigated by the DPPH & ABTS radicals scavenging and inhibition zone assays, respectively. Compared with Ch, the incorporation of WSEO significantly decreased (P < 0.05) the TS, EB, and WVP values, especially when the WSEO ratio reached 1.0 % or higher. Meanwhile, the films exhibited greatly improved visible light barrier performance after WSEO incorporation. Both FTIR spectroscopy and SEM observations reflected the crosslinking between WSEO and Ch. Meanwhile, the composite films demonstrated smaller particle size and weaker rheological viscosities, which enhanced the antimicrobial and antioxidant capabilities when compared with those of Ch. Therefore, this study suggested that WSEO incorporated with Ch is an effective ingredient for the preparation of edible films with enhanced physicochemical and biological properties.